uSDC20D computer on sense details

05-24-2005, 11:10 PM

I have the uSDC20D for my laptop. Is it possible to use a modified USB cable in order to provide the computer on sense signal? Is there a better, more recommended approach for getting this to work with a laptop?

From the instructions:
The Computer On Sense cable consists of a signal Diode that connects from the controller to a 4-pin Molex computer Hard Drive or CD-Rom Power connector connecting to +12 volts. This is how the controller detects the computer is on so that is doesn’t inadvertently turn on/off the computer when it is already on or off. It also allows “Power Down Mode” to be very short. The diode’s polarity points away from the uSDC.

Can I get more details about the specifics of this diode and how it's supposed to be hooked up? I've learned a lot in my trials/tribulations in my install, but this one has me vexed.

I have the uSDC20D for my laptop. Is it possible to use a modified USB cable in order to provide the computer on sense signal? Is there a better, more recommended approach for getting this to work with a laptop?

From the instructions:
The Computer On Sense cable consists of a signal Diode that connects from the controller to a 4-pin Molex computer Hard Drive or CD-Rom Power connector connecting to +12 volts. This is how the controller detects the computer is on so that is doesn’t inadvertently turn on/off the computer when it is already on or off. It also allows “Power Down Mode” to be very short. The diode’s polarity points away from the uSDC.

Can I get more details about the specifics of this diode and how it's supposed to be hooked up? I've learned a lot in my trials/tribulations in my install, but this one has me vexed.

The diode just prevents 12 volts from going into the uSDC and damaging it if you can only use the 12 volt line. If you are connecting it up to 5 volts, you don't need the diode.

What happens, is when the Computer Power supply is off, the 5 volts that is connected to onsense, is pulled to ground by the power supply being off. (No voltage on the 5 volt rail) The diode just lets you use the 12 volt rail too. But because people will try everything under the sun, I just allways reccomend the diode.